#include <stdio.h>

extern FILE *stdin;
extern FILE *stdout;
extern FILE *stderr;

#define LOG "log.txt"

int main()
{
    printf("stdin_fd:%d\n",stdin->_fileno);
    printf("stdout_fd:%d\n",stdout->_fileno);
    printf("stderr_fd:%d\n",stderr->_fileno);

    FILE* fp = (FILE*)fopen(LOG,"a");
    printf("fopen_fd:%d\n",fp->_fileno);
    fclose(fp);
    return 0;
}
